Publications

The field of nanophotonics has seen remarkable advances, with gold-based materials standing out. By precisely fine-tuning the size and shape of metal nanoparticles (NPs), such as gold nanoparticles (AuNPs), it has been possible to gain control over light interaction, modulating localized surface plasmon resonance (LSPR), a phenomenon that involves the collective oscillation of free conduction electrons. This has opened the path toward more powerful biomedical applications, including surface-enhanced Raman spectroscopy (SERS) and photothermal therapy (PTT). When AuNPs dimensions fall below 2 nm, they become gold nanoclusters (AuNCs), losing the LSPR but acquitting fluorescence due to their molecule-like behavior. This unique feature makes them ideal for high-resolution imaging, biomarker detection, and advanced therapies. Beyond traditional uses, the recent inclusion of AuNPs into nanomotors (NMs) enhances precise in vivo tracking and targeted drug delivery. This review highlights the different applications of plasmonic nanomaterials with particular emphasis on AuNPs and AuNCs as a function of their shapes, sizes, and stabilization ligands. Moreover, it dives into the biosensing applications of plasmonic materials by addressing their so-called far-field and near-field optical properties, giving a detailed overview of different high-sensitivity immunoassays and biosensing. A comprehensive outlook on the evolution of plasmonic-based materials for the next therapies is provided.

JTD Keywords: Albumin-gold nanoclusters, Cancer-cells, Gold nanoparticles, Intracellular ph, Microwave-assisted synthesis, Nanoclusters, Nanomotors, Optical-properties, Plasmonic biosensors, Protein-directed synthesis, Rapid synthesi, Resonance immunoassay, Ser, Sers, Silver nanoparticles, Ultrasensitive detection

Here we describe the design and evaluation of a fluidic device for the automatic processing of microarrays, called microarray processing station or MPS. The microarray processing station once installed on a commercial microarrayer allows automating the washing, and drying steps, which are often performed manually. The substrate where the assay occurs remains on place during the microarray printing, incubation and processing steps, therefore the addressing of nL volumes of the distinct immunoassay reagents such as capture and detection antibodies and samples can be performed on the same coordinate of the substrate with a perfect alignment without requiring any additional mechanical or optical re-alignment methods. This allows the performance of independent immunoassays in a single microarray spot.

JTD Keywords: Automation, Customization, High-throughput screening, Immunoassays, Microarrays

The excellent self-assembling properties of DNA and the excellent specificity of the antibodies to detect analytes of small molecular weight under competitive conditions have been combined in this study. Three oligonucleotide sequences (N(1)up, N(2)up, and N(3)up) have been covalently attached to three steroidal haptens (8, hG, and 13) of three anabolic-androgenic steroids (AAS), stanozolol (ST), tetrahydrogestrinone (THG), and boldenone (B), respectively. The synthesis of steroid oligonucleotide conjugates has been performed by the reaction of oligonucleotides carrying amino groups with carboxyl acid derivatives of steroidal haptens. Due to the chemical nature of the steroid derivatives, two methods for coupling the haptens and the ssDNA have been studied: a solid-phase coupling strategy and a solution-phase coupling strategy. Specific antibodies against ST, THG, and B have been used in this study to asses the possibility of using the self-assembling properties of the DNA to prepare biofunctional SPR gold chips based on the immobilization of haptens, by hybridization with the complementary oligonucleotide strands possessing SH groups previously immobilized. The capture of the steroid oligonucleotide conjugates and subsequent binding of the specific antibodies can be monitored on the sensogram due to variations produced on the refractive index on top of the gold chip. The resulting steroid oligonucleotide conjugates retain the hybridization and specific binding properties of oligonucleotides and haptens as demonstrated by thermal denaturation experiments and surface plasmon resonance (SPR).

JTD Keywords: Directed protein immobilization, Plasmon resonance biosensor, Self-assembled monolayers, Label-free, Serum samples, Assay, Immunoassays, Antibodies, Progress, Binding